For many decades, self-propelled combine harvesters have been used by farmers to harvest a wide range of crops including cereals, maize and oil-seed rape. Typically, a combine harvester cuts the crop material, threshes the grain therefrom, separates the grain from the straw, and cleans the grain before storing in an onboard tank. Straw and crop residue is ejected from the rear of the machine.
The collected grain is unloaded into a trailer, parked or driven alongside, via an unloading auger which conveys the grain from the tank(s) to a spout positioned over the trailer. In order to maintain a practical overall machine width, for transport reasons for example, the unloading auger is typically swingable between a stowed position, in which the auger is disposed substantially within the width profile of the combine, and an unloading position in which the spout is positioned at a transverse position spaced away from the combine. Hydraulic actuators are commonly provided to move the auger between the two positions.
To minimise downtime and permit the unloading to be carried out simultaneously to the harvesting operation, tractor and trailer combinations are driven alongside the combine to unload the grain. The increase in header widths over the past years has meant that tractors must space themselves further from the combine during unloading. In turn, this has driven an increase in length of the unloading augers to bridge the increased spacing.
Longer unloading augers place greater demands on their construction and particularly at the elbow due to the increased moment placed thereupon by a loaded auger. To relieve the strain placed upon the elbow joint where the auger attaches to the combine, support devices have been developed to support a portion of the weight of the auger at an intermediate point on its length. Triangulating support struts are often provided at near to the pivoting end of the auger to provide support in both the stowed and unloading positions.
Cradles statically fixed to the combine have also been employed to support a portion of the weight of the auger at an intermediate point when in the stowed position. Such cradles typically offer an outwardly facing ramp which slidingly engages with the underside of the auger when transitioning into the stowed position.
The resistance presented by such cradles when sliding the auger into position places large forces upon the actuator connections sometimes leading to failure. This is compounded by assembly and load variations which make consistent and optimal alignment of the ramp difficult to achieve.